Various substituted phenyl ethers (I′) are known in literature. Q may be uracil, triazine, pyridazine, pyrazole, etc., R may be hydrogen, alkyl, cycloalkyl, alkenyl, or alkynyl. WO 98/41093 and U.S. Pat. No. 6,121,201 describe certain diaryl ethers as herbicides. WO 00/50409 describes herbicidal compounds containing 1-aryl-1,3,5-triazine-4-thione-2,6-dione derivatives. WO 99/14201 describes certain 2-phenyl-3(2H)-pyridazinone derivatives and WO 99/59983 describes certain 6-aryl-3,5-dithioxo-2,3,4,5-tetrahydro-1,2,4-triazine and 6-aryl-3-thioxo-5-oxo-2,3,4,5-tetrahydro-1,2,4-triazine derivatives as herbicides. WO 96/15115 and WO 00/12480 describes a group of substituted phenyl pyrazole derivatives as herbicides. WO 93/15074 and U.S. Pat. No. 5,670,455 describe certain aryl substituted fused pyrazole derivatives as herbicides. 
WO96/07323 and WO96/08151 disclose some known uracil compounds. In WO96/07323 and WO96/08151, the generic representation is significantly broader than the disclosures set forth in them, and in the prior art patents.
However the specific aryl ether compounds of the formula (I) mentioned below are not known and are novel. Furthermore the present invention reveals that the aryl ether derivatives represented by the general formula (I) or their salts have potent herbicidal activity and/or desiccant activity with good crop safety.